Adjustable seats for burgeoning waistlines have been designed for planes.

The seat is called The Morph, and could be adjusted depending on the size of the person sitting in it.

Designed by London-based company Seymourpowell, the chair has two sheets of fabric.

One is for the seat back, and the other for the seat base. They are stretched across the width of an entire row, and over a movable frame.

Armrests and dividers hold the fabric in place, and create three individual "hammock seats".

The dividers slide from side to side, so the fabric is tailored to fit the person sitting in it.

"Passengers who can afford premium, business or first class have a choice and hence some control over their own experience," Seymourpowell's head of transport Jeremy White said.

"For those who travel economy, there is a very limited choice of alternatives. Morph is a solution - a standard product that meets the needs of lots of different kinds of people."

The seat could also be altered for people who simply wanted more space, privacy, or security, White said.

"The young female traveling alone, a mother nursing a child, an elderly or less abled passenger, or a family traveling together, all have specific needs; some desire more privacy or security, some are more vulnerable and require greater assistance, whilst others only need entertainment," he said.

"These needs change too, depending on the time of day, the length of the flight and the reason behind the journey. On the way out, the passenger may need to work, whilst on the way home they may want to relax or sleep. Yet we are all shoehorned into the exact same format, one that has remained unchanged for years."

The company said it was a revolutionary proposition for travellers, with people being able to buy space instead of seats, and being able to trade inches to larger passengers who want more space.

What do you think? Is this the answer to comfortable long-haul travel? Leave a comment.